Confusion regarding slave women awrah with regards to Ali (r.a)'s narration

In the following narration, i have a few issues: Link to the narration below > عَبْدُ الرَّزَّاقِ، > > ١٣٢٠٨ - عَنِ ابْنِ جُرَيْجٍ قَالَ: أَخْبَرَنِي مَنْ أُصَدِّقُ عَمَّنْ، > سَمِعَ عَلِيًّا، يَسْأَلُ عَنِ الْأَمَةِ تُبَاعُ أَيَنْظُرُ إِلَى > سَاقِهَا، وَعَجُزِهَا، وَإِلَى بَطْنِهَا؟. قَالَ: «لَا بَأَسَ > بِذَلِكَ، لَا حُرْمَةَ لَهَا، إِنَّمَا وَقَفَتْ لِنُسَاوِمَهَا» > > Abdul Razzaq, > > 13208 - On the authority of Ibn Jurayj, who said: I was told by > someone whose name I believe, who heard Ali being asked about a female > slave being sold, should he look at her leg, her buttocks, and her > belly? He said: “There is nothing wrong with that, she has no > sanctity, she has only been stopped so that we may bargain over her Regarding the quote above, my questions are as follows: - Is this narration authentic? - Is inspecting slave women awrah (navel to knee) by uncovering halal or haram in slave market? - Also, if i'm not wrong, majority of scholars agree a slave women's awrah is **navel to knee**, then how is looking at the **belly** and **buttocks** permitted? Or is it a translation issue as some say "back" and some "buttocks" or "rump"? Is it talking about over clothes or under? Please also let me know from the Arabic which body parts is it actually referring to. Also is checking private parts (awrah of slave women) allowed?